Objectives: To evaluate which are the most effective procedures to maintain and recover soft tissue health around dental implants. Data sources: The Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE and EMBASE were searched with no language restriction up to June 2007. Handsearching included several dental journals, the bibliographies of the randomised controlled trials (RCTs) and relevant review articles. Review methods: RCTs comparing agents or interventions for maintaining or recovering peri-implant healthy tissues were eligible. Outcome measures were: implant failure, radiographic marginal bone level changes, changes in probing 'attachment' level, changes in probing pocket depth, marginal bleeding, plaque, side effects, ease of maintenance, patient satisfaction, cost, and treatment time. Screening of eligible studies, quality assessment and data extraction were conducted in duplicate. Authors were contacted for missing information. Results were expressed as random effect models using standardised mean differences for continuous data and relative risks for dichotomous data with 95% confidence intervals. Results: Eighteen RCTs were identified. Nine (238 patients) were included. Follow-ups ranged between 6 weeks and 1 year. No meta-analysis could be made since all trials tested different interventions. Listerine mouthwash showed a reduction of 54% in plaque and 34% in marginal bleeding compared with a placebo after 3 months. Conclusions: There was little reliable evidence for which are the most effective interventions for maintaining healthy peri-implant soft tissues. However, it should not be interpreted that current maintenance regimens are ineffective. There is a definite need for trials powered to find possible differences, using primary outcome measures and with much longer follow-up. Keywords: dental implants, maintenance, randomised controlled clinical trial, systematic review